An optical fiber adapter, namely, an optical fiber adapter which may be on both ends thereof inserted with different types of connectors, is widely applied in optical fiber distribution frames, optical fiber communication devices, instruments, etc. The LC adapter is a kind of optical fiber adapter, and is made by using a modular jack-latch mechanism which is easy for operation. Most of LC adapters in the existing art have no function of a light shielding plate, and the cavities thereof are vulnerable to dust and debris. Moreover, the light emitted from an uncovered connector irritates human eyes. Thus, maintenance personnel need to use dust-proof hats to shield the light. The existing art also discloses an LC adapter provided with a light shielding plate. However, such an LC adapter is inconvenient for operation, and the light shielding plate thereof cannot completely fit with the adapter frame, and thus the LC adapter has the defects such as light leakage, incapability of blocking dust, etc.